[PATCH 2/4] MIPS: ath79: pbl: import hornet_1_1_war routine from U-Boot_mod

[Antony Pavlov]

U-Boot_mod is a popular bootloader for Atheros AR93xx chips,
please see https://github.com/pepe2k/u-boot_mod for details.

It's reasonable to import some lowlevel AR9331 initialization
code from U-Boot_mod.

AR9331 (Hornet) 1.1 currently needs an additional
reset at 1st boot. This patch imports necessary code
from u-boot_mod/u-boot/cpu/mips/start_bootstrap.S.

Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
---
 arch/mips/mach-ath79/include/mach/pbl_macros.h | 43 ++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/arch/mips/mach-ath79/include/mach/pbl_macros.h b/arch/mips/mach-ath79/include/mach/pbl_macros.h
index 810f49d..24cfd60 100644
--- a/arch/mips/mach-ath79/include/mach/pbl_macros.h
+++ b/arch/mips/mach-ath79/include/mach/pbl_macros.h
@@ -223,4 +223,47 @@
 	.set	pop
 .endm
 
+.macro	hornet_1_1_war
+	.set push
+	.set noreorder
+
+/*
+ * WAR: Hornet 1.1 currently need a reset once we boot to let the resetb has
+ *      enough time to stable, so that trigger reset at 1st boot, system team
+ *      is investigaing the issue, will remove in short
+ */
+
+	li  t7, 0xbd000000
+	lw  t8, 0(t7)
+	li  t9, 0x12345678
+
+	/* if value of 0xbd000000 != 0x12345678, go to do_reset */
+	bne t8, t9, do_reset
+	 nop
+
+	li  t9, 0xffffffff
+	sw  t9, 0(t7)
+	b   normal_path
+	 nop
+
+do_reset:
+	/* put 0x12345678 into 0xbd000000 */
+	sw  t9, 0(t7)
+
+	/* reset register 0x1806001c */
+	li  t7, 0xb806001c
+	lw  t8, 0(t7)
+	/* bit24, fullchip reset */
+	li  t9, 0x1000000
+	or  t8, t8, t9
+	sw  t8, 0(t7)
+
+do_reset_loop:
+	b   do_reset_loop
+	 nop
+
+normal_path:
+	.set	pop
+.endm
+
 #endif /* __ASM_MACH_ATH79_PBL_MACROS_H */
-- 
2.7.0